Magic2 Final method used for advanced classification Calabrian/tyrrhenian coast in the presence of marine georisks. (DCAT-AP IT)

This document presents the methodology used for the advanced classification of the susceptibility of a portion of the Calabrian-tyrrhenian coast, with the presence/absence of morphobametric elements mapped in the portion of the sea facing the coast itself by the MaGIC project, which can be interpreted as marine georisks. Marine georisks are those processes or events of a geological nature whose effects can involve the seabeds and coasts, of which one can have a trace in the batimorphology of the seabed that has been reconstructed through the activities of the MaGIC project. In this case, the following were considered: a) underwater landslides or offshore faults capable of generating tsunami events; B) heads of canyons or landslides, escarpments of general erosion able to generate both landslides in the coastal-sea sector due to the scratching to the foot by retrogression of the heads or niches themselves, and subtraction of sediment from the coast. To these are added other classification parameters related to the slope of the seabed. The advanced analysis also focused on the correlation between erosive morphologies observed at sea and those present on land in order to identify areas in which marine and coastal morphogenesis appear interdependent with each other. In total, there are 5 classification parameters for which it is possible to attribute three levels of susceptivity: low, medium or high; the coast line has been divided into sections, numbered in a unique and sequential way, to which, for each parameter, the level of susceptivity is assigned. Finally, a more realistic estimate was made of the effects on the coast due to tsunamis generated by underwater landslides, by simulating the propagation of these waves through the open-source tuna numerical code. The methodological approach used is based on the simulation of phenomena occurring in the past and not of events planned for the future, signaling only the general predisposition of the area to the occurrence of events with characteristics similar to those occurring in the past, without any reference to their spatial and temporal frequency.